codeforces 85D. Sum of Medians

/*
    codeforces 85D. Sum of Medians

    正解线段树或是平衡树
    
    结果用vector暴力卡过去了 
     
*/
#include <algorithm>
#include <iostream>
#include <cstdio>
#include <vector>

using namespace std;

void read (int &now)
{
    register char word = getchar ();
    int temp = 0;
    for (; !isdigit (word); word = getchar ())
        if (word == '-')
            temp = 1;
    for (now = 0; isdigit (word); now = now * 10 + word - '0', word = getchar ());
    if (temp == 1)
        now = -now;
}

int N;

std :: vector <int> Flandre;

int main (int argc, char *argv[])
{
    read (N);
    
    static char type[10];
    register long long Answer;
    int x, L;
    for (register int i; N; -- N)
    {
        scanf ("%s", type);
        if (type[0] == 'a')
        {
            read (x);
            Flandre.insert (lower_bound (Flandre.begin (), Flandre.end (), x), x); 
        }
        else if (type[0] == 'd')
        {
            read (x);
            Flandre.erase (lower_bound (Flandre.begin (), Flandre.end (), x));
        }
        else
        {
            L = Flandre.size ();
            for (i = 2, Answer = 0; i < L; i += 5)
                Answer += Flandre[i];
            printf ("%lld
", Answer);
        }
    }
    return 0;
}